It’s been 37 years since a horse won the Triple Crown, but American Pharoah will look to get two-thirds of the way there on Saturday at the 140th Preakness Stakes at Pimlico Race Course. After winning the Kentucky Derby two weeks ago, American Pharoah is the odds-on favorite to win the second leg of the Triple Crown.

American Pharoah started the morning with 4/5 betting odds to win Saturday’s race, and the 2015 Kentucky Derby winner’s odds remain the same just a few hours before the start of the the Preakness Stakes. Firing Line has surpassed Dortmund as the second favorite. Their odds, as well as the odds for other horses, have changed over the course of the day.

Firing Line began the morning with 4/1 odds, but the horse’s odds have improved to 5/2. Dortmund, starting the day at 7/2, has moved to 5/1.

While some horses’ odds might be improving, it will be difficult for anyone to defeat American Pharoah.

"I almost think he has to have some bad luck to lose," six-time Preakness winner D. Wayne Lukas said, via The Baltimore Sun. "I think he's the best horse. You stand here and you're in the race and selfishly you want to do it — I'll try everything in the world to try and beat him — but after you've been in 35 of these you get a little realistic, too."

Tale Of Verve was the biggest longshot of the morning, and that hasn’t changed. The horse's chances of unexpectedly winning the race remain just as unlikely, as Tale Of Verve's odds have stayed at 30/1.

Updated Betting Odds With Post Positions (via The Courier-Journal) 

No. 1 American Pharoah 4/5

No. 2 Dortmund 5/1

No. 3 Mr. Z 14/1

No. 4 Danzig Moon 14/1

No. 5 Tale Of Verve 30/1

No. 6 Bodhisattva 22/1

No. 7 Divining Rod 15/1

No. 8 Firing Line 5/2

Post Time: 6:18 p.m. ET

Actual Start Time: After the horses walk to the gate and the doors are finally closed, it could be close to 6:30 p.m. ET when the race actually begins.